Device for automatically controlling the flow of liquid into a tank

Abstract

The overfill device is of the type comprising a filling tube having a vertical axis and disposed in the tank, a butterfly valve disposed in the filling tube and movable between a vertical opening position and a closing position which corresponds to a bearing of the valve on a valve seat provided in the filling tube, and a float connected to the flap valve and capable of shifting the flap valve between the opening and closing positions, and is characterized in that the valve seat is inclined relative to the vertical axis of the filling tube and the valve is mounted on a pivot pin which is disposed between ends of the valve and is eccentric relative to the vertical axis of the filling tube.

I claim: 
     
       1. A device for limiting the flow of fluid into a tank comprising: a filling tube having a vertical axis and adapted for disposition in the tank for allowing fluid to flow into the tank;   a float that is external to the filling tube   a valve seat disposed in said filling tube and inclined relative to said vertical axis of said filling tube;   a butterfly valve having a top and a bottom face, and at least one aperture, said butterfly valve being disposed in said filling tube, said butterfly valve movable between a vertical open position and a closed position, said closed position corresponding to a bearing of said bottom face on said valve seat;   mounting means for mounting said butterfly valve for pivotable movement about a pivot axis, said pivot axis being eccentric to said vertical axis, so that when said butterfly valve is in a position intermediate said open and closed positions, fluid flowing through said filling tube can impose an eccentric closing force on said butterfly valve which urges said butterfly valve into said closed position;   a relief valve mounted to said butterfly valve and having elastic return means for urging said relief valve to a closed position in which it bears against said bottom face of said butterfly valve to close said aperture; and   connecting means for connecting said float to said butterfly valve so that the weight of said float urges said butterfly valve into said open position, and the buoyancy of said float urges said butterfly valve into a position intermediate said open and closed positions as the tank fills with fluid;   wherein said butterfly valve is subjected to said closing force when in said intermediate position, and wherein said float is lifted upward by the movement of said butterfly valve toward said closing position when said closing force exceeds the force imposed by the weight of said float.   
     
     
       2. The device according to claim 1, wherein said elastic return means comprises a spring mounted on a rod, said rod extending normally from the upper face of said butterfly valve to engage an inner surface of said filling tube as said butterfly valve approaches said open position, said elastic return means urging said butterfly valve away from said open position when said rod is engaged with said inner surface. 
     
     
       3. The device according to claim 1, further comprising a deflector rigidly mounted to the upper face of said butterfly valve and having a curved body that defines a concave side, said deflector being mounted near the perimeter of said butterfly valve so that when said butterfly valve is in said open position, said concave side faces downward and toward said pivot axis; whereby said deflector reduces the closing force imposed on said butterfly valve by fluid flowing through said tube. 
     
     
       4. The device according to claim 1 wherein said connecting means is semi-elastically connected to said butterfly valve. 
     
     
       5. The device according to claim 4 wherein said connecting means includes a "J" shaped member.